Quantum dots (QDs) and other quantum nanoparticles have been prepared and their properties have been documented and described. One proposed use of quantum dots is in the field of biochemistry wherein these particles provide photoluminescent markers for whole cells. In addition, they can be used as markers that allow one to track the activity of individual cellular ligands, for example, organelles or macromolecules.
The essential components in the synthesis of II-VI and IV-VI QDs have remained largely unchanged for 20 years, typically employing tertiary phosphine chalcogenides and metal salts as the reactive precursors. Notable advances include removing the need for pyrophoric compounds and designing ligands to obtain a greater control over QD size, size distribution, and shape. However, the synthetic conversion yield can be very low (<2%) for normal reactions. Also, inconsistencies can arise from the fact that traditional QD syntheses are based on tertiary phosphine chalcogenide molecular precursors, which at temperatures under 200° C. are largely unreactive and thus not responsible for QD formation.
Most current methodologies for the production of II-VI and IV-VI colloidal semiconductor quantum dots (QDs) rely upon the slow addition precursor to nucleated particles for the growth of larger structures. QDs grow larger with time so a reaction must be quenched at a precise time to achieve a desired nanoparticle size. This can be laborious and inexact which is a major source of batch-to-batch inconsistencies and contributes to the very high price (>$100,000 per gram) for commercial sources of quantum dots.